Identification of two fruit yield and fruit size associated QTLs
2Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, Israel
We identified two loci controlling yield, fruit size, and locules number using genome wide association study (GWAS). We validated the quantitative trait loci (QTLs) using genetic markers for each QTL in eight bi-parental F2 populations (200-400 plants in each). The populations were chosen to differ in allele of the specific QTLs and be as similar as possible in the genomic background to prevent unwanted variation. Four populations were chosen to have allelic variation in QTL 1, and two in QTL 2. The last two were chosen to have allelic variation in both QTLs, in order to check epistatic interactions, which were implied by our GWAS results.
The eight populations were grown in a greenhouse experiment during the winter of 2022. We measured the diverse fruit traits on almost 3000 plants in the experiment including ten plants from the parent lines. We extracted DNA from each of the plants and developed parent differentiating markers for each QTL.
The marker for QTL 2 is based on an insertion of 12bp, which co-segregates with the GWAS lead SNP, and is found within the coding region of a gene in the QTL.
The marker characterization of F2 plants is currently in progress. In one population the fruit size trait is significantly associated with the marker for QTL 2.
Next, we will study the spatial and temporal gene expression of candidate genes which are located in the QTLs. We will also use transgenic plants, generating overexpression and loss of function knock out lines.